This invention relates in general to a device for measuring the movements of a component in a drive train system that generates power from a source and transfers such power from the source to a driven mechanism. In particular, this invention relates to an apparatus for measuring the movements of an axle housing in a vehicular drive train system during operation.
Drive train systems are widely used for generating power from a source and for transferring such power from the source to a driven mechanism. Frequently, the source generates rotational power, and such rotational power is transferred from the source to a rotatably driven mechanism. For example, in most land vehicles in use today, an engine/transmission assembly generates rotational power, and such rotational power is transferred from an output shaft of the engine/transmission assembly through a hollow cylindrical driveshaft tube to an input shaft of an axle assembly so as to rotatably drive the wheels of the vehicle. To accomplish this, a first universal joint is usually connected between the output shaft of the engine/transmission assembly and a first end of the driveshaft tube, while a second universal joint is usually connected between a second end of the driveshaft tube and the input shaft of the axle assembly. The universal joints provide a rotational driving connection from the output shaft of the engine/transmission assembly through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of misalignment between the rotational axes of these three shafts.
The various components of these vehicular and other drive train systems are usually supported on or connected to a frame assembly or other rigid support structure so as to be generally fixed in position relative to one another during use. However, in many instances, the drive train system may be designed to accommodate limited amount of movement of one or more of the components of the drive train system relative to the others. For example, in a commonly known vehicular drive train system, the engine/transmission assembly is secured to the vehicle frame assembly so as to be essentially immovable relative thereto, while the axle assembly is resiliently connected to the vehicle frame assembly for movement relative thereto, such as when bumps in the road are encountered. Thus, the axle assembly is permitted to move a limited amount relative to the engine/transmission assembly under normal operating conditions.
Furthermore, it is known other relative movements of the drive train system to components can occur under certain operating conditions. For example, when relatively large torsional loads are transmitted through a vehicular drive train system from the engine/transmission assembly to the axle assembly, such as can occur during rapid acceleration of the vehicle, the axle assembly may pitch or rotate slightly relative to the remainder of the vehicle. Similar pitching or rotating movements of the axle is assembly can occur during relatively rapid deceleration of the vehicle, such as when the brakes of the vehicle are applied). These and other dynamic movements of the axle assembly relative to the remainder of the vehicular drive train system can, if sufficiently large in magnitude, result in undesirable operating conditions. For example, the above-described relative movements of the axle assembly can result in undesirable tension and compression of the driveshaft tube, and can also cause the operating angles of the universal joints to become undesirably large.
Most vehicular drive train systems are designed to accommodate a certain amount of such relative movements. For example, a slip joint may be provided in the drive train system to prevent excessive tension and compression of the driveshaft tube that might otherwise result from such relative movements. However, it is known that the magnitudes of such relative movements can vary widely from vehicle model to vehicle model as a result of a variety of factors, such as suspension characteristics, vehicle weight, and the like. To insure that the drive train system is always operated within predetermined design parameters, it would be desirable to provide an apparatus that is capable of measuring the movements of a component in a drive train assembly, such as an axle housing in a vehicular drive train assembly, for subsequent evaluation.
This invention relates to an apparatus for measuring the movements of a component in a drive train assembly, such as an axle housing in a vehicular drive train assembly. The apparatus includes a motion transfer member having a first end that is connected to the axle assembly for movement therewith. A second end of the motion transfer member extends from the axle assembly into engagement with a measuring device that is supported co-axially with or relative to the axle assembly. The measuring device is responsive to the movements of the axle assembly for generating a signal that is representative thereof. The electrical signals generated by the measuring device are fed to an electronic controller for storage and/or analysis.